Petard missile



Dec. 24, 1946. J. CHURCH AL 2,412,967

PETARD MISSILE Filed April 23, 1941 I9 I /.9 l9

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LILEJJH H. Church WilfredElT'hibudeau 5 y M M Patented Dec. 24, 1946PETARD MISSILE Joseph H. Church, Austin,

E. Thibodeau,

13 Claims.

Min and Wilfred Cleveland, Ohio Application April 23, 1941, Serial No.389,923

(Granted under the act amended April 30,

The invention described herein may be manufactured and used by or forthe Government for governmental purposes, without the payment to us ofany royalty thereon.

This invention relates to explosive missilesyand in particular to apetard to be applied from a distance.

Petards have been known from the earliest days of gunpowder. Theyconsisted of a hoodshaped or bell-shaped container with a planar rim atthe large open end for application at the face of the work to beblasted, and were filled with an explosive which was set off from theapex end of the petard. The peculiar destructive action of a petard isdue to the fact that the container holds the explosive at the face ofthe object to be destroyed for a very small time interval which issuflicient to give direction to the blast. After this very small timeinterval, the container may fall away or recoil, but the main result ofdirecting the blast has already been accomplished. Early petards wereheavy affairs as to the container and thus lent some degree of emcacy byreason of their inertia. However, the provision of a heavy container isburdensome and unnecessary since a petard will function as well with alight container, especially when a close seal is maintained between thepetard rim and the target. Petards have been used in underwaterblasting, wherein the weight of a column of water lends its inertia tothe holding of the container during the necessary time interval. Atdetonating, and even defiagrating, time intervals, the inertia of theatmosphere becomes appreciable for this purpose and petards with lightcontainers have been used in modern blasting (Patent No. 1,440,601). Asnoted in the aforementioned patent, a dead air space at the blastingface forms a desideratum of petard practise, and this well-knownexpedient is contemplated in the petards of the present invention. Thepatent further advises that the striking gap may be varied in shape andvolume to secure different effects. In this regard, the teaching inZeitschrift fur clas gesamte Schiesse und Sprengstofiwesen, May 15,1914, pages 183-187 will be found of considerable importance.

In a military sense petards have been used in the past to good advantagein siege work to batter down doors and other obstacles. In these cases,the petard, usually a cumbersome object, was carried by the petardier toa stationary object and secured, facing thereto, or positioned as with abipod and sling, and touched off. In modern warfare it becomes desirableto perform demoliof March 3, 1883, as

tion work on moving fortresses such as tanks or other automotivevehicles, ships and aeroplanes, armored or otherwise. Application of apetard in the case of moving targets would necessarily take place from aremote position, a procedure heretofore not considered.

Petards are particularly well adapted for use as comparativelyslow-moving offensive missiles, in which in a more modern view, emphasisis placed upon penetration rather than demolition work. The flat-facedmissile is, therefore, mainly a carrier for an explosive which is,itself, designed to effect penetration, and the missile, by its shape,serves to position the explosive at the target for most effectiveresults. With a large area of explosive presented to the target atimpact, penetration is enhanced, even at glancing angles of impact.However, the optimum case will obtain where the explosive body isdetonated with its axis perpendicular to the target and. the fiat-facedmissiles are admirably adapted to swing into such position in the casewhere angular contact is made. However, such a righting action will nottake place if the projectile rebounds or ricochets from the target. Arebound or ricochet would also vitiate the delicate matter of timing ofthe detonation of the main charge, important in penetration missiles ofthe type herein described.

We have found that by including on the front face of our missile,especially at the rim, a leading impact unit of a material of lowresilience, or of a hollow structure to simulate, by collapsing, theshock-deadening effects of a material of low resilience, the missile isimproved in its functioning as regards impact and penetration. Thecalculated timing is preserved and the detonation takes place with themissile at a favorable angle. Furthermore, such agleading impact unitwill serve to hold the face of the missile in sealed relation with thetarget for the small period of time between impact and detonation whichis requisite for petard action. This full rim contact for petard actionis but a cumulative incident in the series of advantages presented bythe shockabsorbing impact member of the invention. If lead is used as animpact unit, a further advantage is noted in that the center of gravityof the missile will be moved forward, especially where a light containeris employed, and aid the missile in aligning itself in flight for properapproach to the target with a view to petard action. Soft noses onogival projectiles are common, but their use was never conceived withsuch problems in mind as are dealt with in the present invention whichconcerns a faced missile. The problem of vision of a percussion firingunit which is so coordinated with the impact face of a missile as toremain unarmed after impact until or unless the missile is alignedperpendicular to the target.

It might well be mentioned that toy darts are known which are built witha target-gripping cup, usually of rubber, but these do not involveproblems attending the use of an explosive, nor are they concerned withpenetration of a target or other objective. Neither do they involve animpact unit of low resilience which will bring about a deceleration ofthe missile without rebound.

The petard of the present invention is distinguished from known devicesof a similar nature in that it is essentially a petard missile forapplication from a distance and-carries an impact firing means. It isbelieved that such a combination spells a novel concept in the art.

It is therefore an objectof the invention to provide a plane-facedexplosive missile with a non-resilient, shock-absorbing impact member.

It is a further object of the invention to provide a petard missile witha coronal impact member of shock-dissipating material.

It is a further object of this invention to provide an explosive missilewhich will align in flight, decelerate at the target, align itself andadhere thereto, or respond in any combination of these functions as theexigencies require.

It is a further object of the invention to provide a petard forapplication from a distance, and having impact firing means.

It is a further object of the invention to provide an explosive missilewhich will fire only when positioned normal to the target.

To these and other ends, the invention conists in the construction,arrangement-and combination of elements described hereinafter andpointed out in the claims forming a part of this specification.

A practical embodiment of the invention is illustrated in theaccompanying drawing where- Figures 1, 2 and 6 are elevational views,partly in section of petard missiles.

Figures 3, 4 and 8 are fragmentary views, partly in section of petardmissiles in elevation.

Figure is a detail of a firing mechanism in sectional elevation.

Figure '7 is a detail showing a modification of the device of Fi ure 6,and

Figure 9 is a modified firing mechanism for use in a missile such asthat of Figure 6.

Referring to the drawing by characters of reference, there is shown inFigure 1 a missile composed of a cup-form main body I. An explosivecharge is held therein by a closure member 2, partially shown in thedrawing. The particular shape of inner containers or closure mem- .bersforms no part of the present invention. The closure member, forinstance, may be flat or it may be formed with a hollow charge as shownin British Patent No. 28,030 of 1911. v A rear stem pin 9 of appreciablemass.

preferably lead, but which may be constructed of other shock-deadeningmaterials, such. as copper, felt, pressed paper, or various plastics. orit may consist of loose material such as shot or sand confined in acontainer. The anti-skid features of the annulus 5 are enhanced by theaddition of an annular trough 3 on its front face. Instead of an annulartrough, a series of circular cup-like depressions may be employed in thefront face of the annulus 5.

In the rear stem 3 is located the percussion firing means operating onthe inertia principle. Within stem 3 an inner sleeve 1 with closedbottom 8 isthreaded. Slidably received in sleeve 1 and resting on thesleeve bottom 8 is a firing The firing pin 9 is immobilized by shearpins l0 and is additionally secured by a pull pin Hr passing through thestem 3, sleeve I and firing pin 9. Threadedly received in the top ofsleeve 1 is another sleeve I2 carrying a primer capsule l3. Prior tooffensive use of the missile, the pull pin H is withdrawn, and on impactthe pins [0 are sheared while the firing pin 9 continues into the primeror detonating capsule 13.

In Figure 8 is shown the rim of a missile generally similar to that ofFigure 1, but wherein the shock-absorbing impactmember is provided witha flange l4. Considerations of design may require that the missile bodyproper bear a high length/width ratio which would not favor retention ofthe missile in righted position after inclined impact on' the target,but rather a continued tumbling. The flange operates to reduce thisratio at the impact section and hence lower the probability of continuedtumbling. The flange may be employed on any of the modifications shown.

In Figure 3 isshown a missile like that of Figure 1, in which theshock-deadening annular member [5 is of sheet material lapped about therim of the body and keyed therein by indentations as at I6, leaving ahollow space I! above the rim.

, Here, the first action of the shock member I5 on 3 is indicated on themissile. This may be a handle for carrying and manual delivery, or anyconventional unit for attachment to a projecting device. Received aboutthe rim 4 of the body I is an annulus 5 of a non-resilient material,

impact is to deform in shape, followed by compression. This initialchange of shape serves to further soften the shock and lengthen the timeof deceleration of the solid body, thus adding time for righting themissile prior to detonation.

In Figure 2 is shown a form of missile in which the priming isaccomplished by relative forward motion of an inner charge containerwith respect to the outside framework. An inner explosive container I8is carried in a framework comprising longitudinal bar members l9 heldrigidly in spaced relation by a ring member 20. The forward rim ofcontainer 18 is spaced rearward of the forward ends of bars 19 andwithin the step formed by members I8 and I9 is placed a tubularshock-deadening member 2|, protruding forward of all other frontmembers. The tube 2| is shown as welded or soldered, but may be rivetedor secured by any other fastening means.

The bars [9 are integral with a tubular tail piece '22 about which isthreaded a tubular handling member 23 having a threaded closure plug 24held therein. The explosive container 18 threadedly carries a tubulartail piece 25 which is slidably received in the tail piece 2!. Tube 25contains priming material 26 within which is contained a smooth portionof a friction pull igniter 2'lhaving a serrated or otherwise roughenedportion 28 above the priming material and a lower bent portion receivedin slots 29, 30 in the tubes 25 and 22 respectively. The thickness ofthe shock member igniter 21 is slightly greater than'slots 28, so thatwhen handling member 23 is screwed up tightly the igniter 21 is securelyheld against the tube 22. Upon impact, the charge-carrying member I8will advance, crushing the shock tube 2| and carrying primer 26 pastserrations 23 to ignite the primer. function in the same general manneras the annulus 5 of Figure 1.

In Figure 4 is shown a fragment of a missile of the same general type asthat of Figure 2 wherein 3| is a tube of coiled section, and has aportion 32 extending into an opening 33 between the charge member I9.more work on This form requires considerably the shock member before thecontainer I 8 can advance to charge-initiating position. Obviously otherforms of initiators than that shown in Figure 2 may be employed.

In Figure 6 is shown an explosive missile with a firing unit designed toset only when the missile is axially perpendicular to the target. Thisisaccomplished by a coordination of the crown-shaped forward end ofthemissile with the primer-actuating unit. A cup-like main chargecontainer 34 threadedly carries a tail piece 35 having a primer 36, aspherical bolt 31 and a screw plug keeper 38. The spherical bolt 31 hasa central bore 39, and in this bore is slidably fitted a firing pin heldagainst a spring 4| under full compression by a shear pin 42, and, inaddition, by a pull pin 43 extending through the sphere 31 and the tube35.

Encompassing the outside of container 34 is a series of longitudinalstrips 44 attached at their forward ends to a ring member 45 as by aturned end 46 fitting in an annular channel 41 in the ring, or inindividual recesses, passing through cases, especially where thecurvature of the missile is slight. In such case, also, the sphere maybe engaged by the strips in pockets in its lower hemisphere.

A shock-deadening impact unit 5:1 is fixed to ring 45 and the forwardrim of container 34.

Assembly is easily effected by inserting firing pin 40 into the sphere31 against spring 4 i, which when fully compressed forms a guard againstsetback forces, and inserting the shear pin 42. The sphere 31 is thenplaced in tube 35 and pull pin 43 inserted. Plug 38 and primer 36 arethen added. Strips 44 are then threaded ever, if the missile has hit thetarget at a glancing angle, the outer portion of shock-deadening member5| and ring 45 will first yield without affording the proper stoppage toshear the pin 42. Thus those strips 44 nearest the point of contactcontainer l8 and the outer The shock member 2| will 1 tion of the impactrim 5| 6 will operate proportionately to their proximity to the point ofimpact and the angle of the impact, to swing the spherical bolt 31 andcause the opposite strips to recede and raise that poropposite the pointof impact. With the turning of the bolt 31 the firing pin 40 is directedaway from the primer, and when the full shock of impact comes through 31and permittingspring 4| to force firing pin 40 into the primer. Sinceprimer, flange 52 is chamfered as at 53 to regulate the sensitivity toangle of detonation.

It will be understood that the pockets 49 will be of such size as tooffer no substantial hindrance to the ends of those strips 44 which area complete annular shoulder and a. neck portion. In Figure 7 is shown adetail of a modification the bars 54 meet the target prior to the bodyportion to unarm the firing mechanism as explained in connection withFigure 6.

In Figure 5 is shown another form of firing mechanism. A tubular tailpiece 51 with closed bottom 58 has a through perforation 59. Anextension 60 of the tail piece 51 is telescoped thereabout and carries apin 6| which passes through the perforations 59. Pin 6| passes throughand carries a slidable firing pin 62.

may be removed under setback forces or manually, in the latter case, bymotion forward or rearward. The arms 53 may be of spring material withposition of on removal of the band 66. springy or otherwise, may havetion with ends within the perforations 59 in which case the missileremains safe even with the band removed until a sufficient shock isencountered to force arms 63 outward by tail 5'! acting on slantsurfaces 61 of bent ends 65. The slant surfaces should be so designed asto function only at impact forces.

In the embodiment shown in Figure 6, the firing mechanism may beconsiderably simplified by omitting the spherical bolt. As shown inFigure 9 the firing pin 40 moves in a bore 68 in a tail piece 69. Thistail piece 69 is threaded into a plug 10 which is threadedly held in thebody 34. Plug 14 and tail piece 63 are spaced to accommodate a. ring 1|of internal diameter equal to or slightly greater than bore 68, and topermit transverse sliding of said ring. Bars 44 pass through bores 12 inplug 10 and contact the ring 1|. At glancing angles of impact of themissile the ring 1| will be forced by some of the bars 44 into the pathof the firing pin and will be' restored to normal position, clearing thepin, when the missile is brought to full-faced engagement, as in Or, thearms 53, their normal posithe case of Figure 6. The sensitivity may beregulated by chamfering the ring as at 13.

We claim:

1. A petard of the type designed for front explosion comprising anaxially symmetric body, percussion fuse means and an explosive chargetherein, an axial tail piece adapted for handling the petard, aprojecting annular rim forward of the petard defining a fiat impact faceof substantial cross section with respect to the petard, and an annularshock-deadening unit of low resilience with respect to that of thepetard fixed to said rim on an annular line concentric with said rim andextending forward thereof.

2. A petard of the type designed for front explosion as in claim 1 inwhich said shock-deadening unit comprises lead.

3. In an explosive missile having a faced impact portion with projectingannular rim onthe said portion, ,an annular shock-deadening membercomprising a crown piece looped over and enveloping the said rim, saidmember comprising a material of low resilience relative to the materialof the missile.

4. A petard missile of the type adapted for front explosion comprising acontainer having an opening and a planar impact portion defined by a rimof the container at said opening, an explosive charge in said container,a closure member in said opening confining said explosive charge, and anannular shock-deadening unit of low resilience with respect to thematerial of said container on said rim only of said container andextending into the opening and overhanging said closure member.

5. An explosive missile having a rim-shaped impact portion and rearpercussion firing means, said firing means comprising a universallymounted bolt, a recess therein, a primer adjacent said recess and afiring pin in said recess, held against spring pressure by a shearablepin, spaced longitudinal impact transmission members connecting saidimpact portion and said bolt whereby to swing said bolt recess out ofalignment with said primer when less than all of said transmissionmembers are actuated at impact.

6. An explosive missile having a faced impact portion, a spring memberin the rear of said missile, a firing pin forward of said spring andshearable means holding said firing pin against the pressure of saidspring, blocking means in advance of said firing pin and movable intoand out of the path thereof and spaced members ex, tending from theperiphery of said faced impact portion to the said blocking means andslidable longitudinally relative to said missile to move said blockingmeans at oblique impact of the missile.

'7. An explosive missile as in claim 6 wherein said blocking meanscomprises a ring with inside diameter sufficient to pass the firing pinand normally surrounding the path of travel thereof.

8. In an explosive missile, a firing means comprising a tubular tailpiece fixed to said missile and having a closed bottom, diametricallyopposite openings in said tail piece, a tube telescoped on said tailpiece, a firing pin in said tail piece, a pin passing through saidfiring pin, openings and tube, arms fixed to the exterior of said tubeand having ends bent over the top of said tube and engaging saidopenings, and a band surrounding said arms and holding said bent ends insaid openings.

' 9. An explosive missile comprising a fiat front impact portion and apercussion firing means, compressed spring means tending to move saidpercussion means to firing position, shearable means holding saidpercussion means prior to impact, spaced movable impact members on themissile and an operative connection between said impact members and saidpercussion means, said operative connection arranged to disarm thepercussion means from firing position after shearin of said shearablemeans by impact unless or until the said impact means makes fiat contactwith a struck target.

10. A petard missile of the type designed for front explosion,comprising a body having a flat impact portion and having an annularmember of material of low resilience with respect to that of the missilesecured to saidimpact portion and extending slightly beyond saidportion, to efiect sealing contact between said impact portion and astruck target, deaden the shock of said missile, and inhibit rebound,and impact firing means in said missile.

11. A petard missile of the type adapted for front explosion comprisingan explosive charge, a handling portion for engagement with a projectorand a fiat faced front portion, an annular shock deadening unit of lowresiliency relative to the material of the missile, for impact with atarget, peripherally attached to and protruding forward of said fiatfaced portion, said shock deadening unit being of a diametersubstantially commensurate with the largest diameter of the missile, andan impact firing means at the rear of the missile.

12. A petard missile of th type adapted for front explosion, as in claim11, wherein the shock deadening unit comprises lead.

13. In combination, a petard missile of the type designed for frontexplosion comprising a hollow body containing an explosive charge andhaving a front fiat faced end of substantial cross-sectional area,impact firing means in the base of the missile and an annular shockdeadening unit of low resiliency with respect to the material of themissile on the front of the missile and of a diameter commensurate withthat of the missile adapted to seal the missile against the target uponimpact of the missile.

JOSEPH H. CHURCH. WILFRED E. THIBODEAU.

